The giant of the microfinance world, ACCION provides partners in 25 nations with technical assistance, financing, and guarantees. Those institutions, in turn, will support 3 million entrepreneurs this year with loans of typically less than $1,000. The idea: Tiny investments, multiplied on mass scale, drive huge gains in income and employment.accion.org

Merging market forces with humanitarian instincts, Acumen funds entrepreneurs offering critical services to people living on less than $4 a day. Its 24 investments--in enterprises ranging from a maker of antimalarial nets in Tanzania to a Pakistani builder of low-income housing--have created more than 20,000 jobs and changed an estimated 10 million lives. Novogratz's goal: to reach 50 million people by 2011.acumenfund.org

At Aspire's California charter schools, kids are taught from day one of kindergarten to set their sights on college. And they do: 97% of the graduates from its five high schools since 2004 has been accepted, and more than half ultimately get college degrees--compared with 6% of their neighbors. Credit the high expectations, required college-level classes, and motivated teachers. Plus, Shalvey says, students "transition from hope to existence proof" by seeing Aspire-educated siblings and friends succeed.aspirepublicschools.org

It sounds simple: Pay attention to underperforming low-income students, and they'll do better. BELL proves the case. Kids enter its after-school programs at the "failing" reading level, but 81% graduate at "proficient" or higher. Summer "scholars" gain an average of four months' grade-equivalency skills. No wonder that when Senator Barack Obama introduced his STEP UP Act to fund summer education, BELL was one of the models.bellnational.org

The math is powerful: Invest $10,000, create 50 jobs--and pocket $300. Calvert targets investors who will accept below-market financial returns if they know their capital is serving a greater good. It raises funds via Community Investment Notes paying up to 3% interest, then lends the money to nonprofit groups. Since 1995, such investments have built 10,000 homes and created more than 230,000 jobs.calvertfoundation.org

Ceres's Global Reporting Initiative has become the standard for corporate reporting on environmental and social issues; some 1,200 companies worldwide have adopted the format to account for their environmental impact. More than that, Ceres pressures companies to do better, sparking lower energy consumption, improved governance on environmental issues, and fostering $1.5 billion in clean technology investments.ceres.org

Graduates of Citizen Schools' Eighth-Grade Academy are almost three times as likely as their peers to enroll in college-track high schools. Why? Citizen Schools provides structured, project-based apprenticeships in areas such as business, journalism, and community service. More than 3,000 low-income kids in six states get instruction after school and on weekends from 2,800 volunteers.citizenschools.org

Since 1988, City Year has dispatched high-octane teams of 17-to 24-year-olds to urban schools and neighborhoods. Some 1,300 young people will spend this year tutoring and mentoring in schools and renovating neighborhoods in 18 U.S. cities, with 200 more in Johannesburg, South Africa. The goal is to make a difference, of course, but also to build corps members' civic awareness and leadership skills.cityyear.org

Civic Builders buys dilapidated buildings in New York--its five so far include an abandoned ice cream factory in Brooklyn--and gives them new life as state-of-the-art schoolhouses that it leases to charter schools. It negotiates municipal real-estate bureaucracy, allowing school staff to focus on curriculum and staff development.civicbuilders.org

Life after 60? Civic Ventures promotes "encore careers" for baby boomers who have hit traditional retirement age but still want or need to work. Its Experience Corps assigns 1,800 graying Americans as tutors and mentors in urban public schools, and the Purpose Prize each year invests $100,000 in five over-60 social entrepreneurs. Freedman's goals: to expand opportunities for a generation and to alter the national discussion on aging.civicventures.org

Why don't many poor kids go to college? It's less about money than support and experience. College Summit helps schools build their capacity to guide low-income students through the process, with peer counseling, postsecondary planning courses, and four-day workshops at colleges. Some 79% of participants enroll in universities. Winner, 2008 Outstanding Social Entrepreneur, from the Schwab Foundation for Social Entrepreneurship--which each year selects one Social Capitalist Award winner to join its network and attend the World Economic Forum in Davos, Switzerland.collegesummit.org

Solving homelessness is about more than just building homes. Common Ground develops affordable housing, but it also leverages a network of volunteers and corporate sponsors to provide homeless men and women--4,000 since 1990--jobs, rehabilitation services, and community. London and Toronto, among other cities, have embraced its model.commonground.org

Seven years ago, Minneapolis's Lake Street corridor was a strip of brothels and abandoned warehouses. Then, CRF kicked in: It buys up loans held by community-development organizations, then pools them into lower-risk instruments sold to institutional investors. Local agencies use the proceeds to make more loans that can revitalize neighborhoods. Minneapolis's original $500,000 in capital has been recycled into loans totaling $22 million.crfusa.com

This online matchmaker developed an early and successful strategy to harness the Internet for philanthropy. School teachers post their wish lists on the site--art supplies, say, or a class trip to the zoo. Donors browse through the projects and fund the ones they find most compelling. Since 2000, the nonprofit has delivered more than $13.7 million to public schools. Someday (we hope), it could outmode bake sales.donorschoose.org

Endeavor identifies and supports high-impact entrepreneurs in emerging markets around the world, connecting them to mentors, consulting advice, and investment. The idea: Given advice and opportunities, energetic entrepreneurs with scalable products can yield outsized effects on local employment and wealth. In fact, since 1997, Endeavor Entrepreneurs have created more than 79,000 jobs paying an average of 10 times the local minimum wage.endeavor.org

Give Zimmer a dollar, and she'll get a book to a low-income child. Through networks of community groups and a Web marketplace, First Book has distributed more than 51 million books. "There is a hunger for the resources not to be believed," Zimmer says; one offering of 300,000 donated books was snatched up online within 20 hours.firstbook.org

This holiday season, give a friend the gift that keeps on qucking. Or Mooing. Heifer provides poor families worldwide with "living loans"--livestock, crop starters, and saplings--and trains them to make the most of their new asset. Beneficiaries must donate their animal's offspring to others, creating a cycle of development. According to an independent 2005 report, Heifer participants enjoy better health and higher educational achievement over time.heifer.org

Since 1990, the network has supported construction of more than 500,000 homes, linking 92 independent nonprofit housing developers to capital and providing homeowners with mortgages, insurance, and other services. Now, Bledsoe is taking the network into education via the Charter School Financing Partnership, offering competitive loans to public charter schools. That initiative, which aims to finance 15,000 student-seats over four years, just won a $15 million U.S. Education Department grant.housingpartnership.net

This real-estate lender to the nonprofit world makes below-market property loans to organizations that serve low-income and special-needs communities. Since 1990, IFF has financed or developed more than 7 million square feet of space, saving clients $16 million in interest or consulting fees. It also helps borrowers secure land, navigate zoning restrictions, and choose contractors.iff.org

Cleveland has big plans for Jumpstart, which attacks illiteracy by recruiting and training adults to mentor low-income preschool kids. "We've helped more than 50,000 children, but why not 300,000?" he asks. Cleveland wants to diversify Jumpstart's endowment by getting more government funding, and by rallying public support for early childhood education through promotions like the "Read for the Record" campaign.jstart.org

Few low-income kids nationally attend college; for graduates of KIPP Academies, the rate is close to 80%. Why? KIPP recruits and trains leaders with both business acumen and educational chops to open and run its schools. Students spend 60% more time in school, and they're expected to succeed. Now with 57 schools, KIPP plans to double within five years. The secondary effect: By building multiple schools in targeted areas, it challenges public systems to improve.kipp.org

When disaster strikes--war, disease, acts of God--Mercy Corps follows. Today's primary battle zone: Africa, where its staffers are providing shelter and clean drinking water to displaced thousands in Darfur and the Democratic Republic of Congo, and helping AIDS orphans in Zimbabwe go to school. In 35 countries, often working with corporate partners like Nike, it builds homes, finds jobs, and offers emergency relief, serving more than 14.4 million people since 1979.mercycorps.org

There are more than a million nonprofit charities out there in the U.S. Network for Good is a low-cost, online hypermarket that connects all of them to donors and volunteers. In six years, has distributed more than $145 donations and referred 300,000 volunteers. New this year: an offshoot sixdegrees.org, that lets you embed donation link to your favorite charity your emails, Facebook page, and "It's easy to be a consumer online," Strathmann says. "It should be easy to be a philanthropist online."networkforgood.org

NLNS recruits outstanding educators and professionals from other fields with prior teaching experience to serve as public school principals in nine cities. Schnur wants to "transform the urban principalship" via rigorous training, a mandatory residency program, and an ongoing in-house support network. "Our goal," he says, "is to have dramatic changes--from bad to great--in all our schools."nlns.org

Its Teaching Fellows Program recruits and trains accomplished non-education professionals to launch new careers teaching in urban public schools. Provides school districts with consulting on chronic staffing shortages, bureaucratic inefficiencies, and hiring practices--the better to keep those faculty. It has placed 23,000 teachers since 1997, including nearly a quarter the math teachers in New York.tntp.org

After Japanese encephalitis killed 1,800 people in India in 2005, PATH worked with Chinese manufacturers to distribute an inexpensive vaccine to 30 million children. That's classic PATH: For more than 30 years, it has been central to some of the most innovative medical solutions--high-nutrient rice, clean-delivery birth kits, needle-free injection devices--in the developing world, typically with for-profit partners.path.org

Driven by a belief in the power of moderation, Peaceworks (originally funded by a company that markets food produced in strife-ridden countries) trains young Israeli and Palestinian activists in conflict resolution and consensus building, and uses Web and video technology and other grassroots initiatives to mobilize voters in support of peace.peaceworks.net

A merger created a volunteer network of 370 "civic hubs," linking 60,000 nonprofits around the country. Points of Light connects those organizations with people who want to volunteer, managing more than 50,000 service projects a year. As Nunn points out, Americans need some remedial training when it comes to this realm: One in three who volunteered in 2005 quit the following year. She wants to win new recruits by building systems that better link volunteer hubs, and by reaching out to both tech-savvy youngsters and retired boomers.handsonnetwork.org

"The ability to penetrate down to the very extreme level of the periphery of the local society or market is pretty satisfying," says Hofmann, a State Department veteran and former ambassador. In 2006, PSI says it helped avert an estimated 209,000 HIV infections and 212 million episodes of diarrhea in the developing world. Once focused solely on population control, its public health campaigns now target malaria, AIDS, and drinking water quality by distributing low-cost bed nets, condoms, and water-purification kits.psi.org

How to work America's civic leadership muscle? Public Allies enlists young people to do 10-month stints at nonprofits and trains them in collaborative leadership. The key is recruiting talent that represents a community's breadth: 67% of participants are minorities, 60% are women. "The pipeline needs to include everybody," Schmitz says. The impressive result: More 80% of the program's alums stay public service.publicallies.org

How much does it cost to make kids better readers? About $28 apiece. Raising a Reader sells kits that contain red tote bags packed with four books, plus curricula. Each bag circulates among families, encouraging parents to read to their children. It works: Participating tots visit libraries more often and score higher on reading comprehension.raisingareader.org

Its locally run marketing campaigns motivate villages in 40 developing nations to conserve natural resources and protect endangered species. The multichannel campaigns have reached more than 6.5 million people in some 2,000 communities. The next frontier: southern China, where Rare has partnered with government officials to promote alternatives to stripping forests for wood fuel.rareconservation.org

Reach Out and Read takes the illiteracy into doctors' offices. Participating medical clinics, young low-income children get a free book checkup. Doctors and nurses are trained to promote early literacy parents--and thousands of volunteers read to kids while they're waiting, showing parents how it's done. Program says it reaches 25% of children in the U.S.reachoutandread.org

"Between the time you go to bed and wake up," Wood says, "we've opened a new library." Room to Read has built 1,600 just this year; the 5,000th is set to open by year-end. Stocked with donated books, the libraries reach 1.5 million children, mostly in Southeast Asia. Wood, a former Microsoft exec, wants to double that total by 2010.roomtoread.org

Formerly known as Eco-Logic Finance, Root Capital provides affordable loans to food producers in developing countries, encouraging them to avoid unsustainable strategies like slash-and-burn farming. "Everyone wins: small farmers get the money they need, socially oriented investors such as Starbucks and Green Mountain Coffee Roasters help specialty product growers, and there's less damage to the environment," Foote says. Root Capital has made more than 350 loans totaling over $65 million, with a repayment rate of 99.5%. His biggest challenge? Keeping up with surging demand for financing.rootcapital.org

A one-stop solution for people "cut out of the mainstream," as Aubry puts it, Rubicon provides 4,000 poor, homeless, and disabled people with housing, money management, substance-abuse recovery, and legal counsel. It also trains and places those people for work, sometimes at its two social enterprises: Rubicon Landscape Services and Rubicon Bakery. Now it's developing a third venture, set to debut in 2009.rubiconprograms.org

When S.K. Mahmood's eyesight began failing, his work as a roadside tailor in rural India suffered--as did his ability to support his wife, his mother, and five kids. He got help from Rama Devi, a Scojo "vision entrepreneur" who sold him a $3 pair of reading glasses. Scojo has set up 1,000 entrepreneurs, mostly women like Devi, with microfranchises in nine countries. (They pay Scojo $2 apiece for the glasses, which cost $1 to make.) Scojo's goal: to sell 1 million pairs within three years.scojofoundation.org

SEED's innovative model combines private and public financing to create free college prep boarding schools for underserved urban children. Its first, in Washington, D.C., has seen every graduating senior since 2004 admitted to a four-year college, with approximately 65% on track to get degrees. A second academy is finally set to open in Baltimore next year.seedfoundation.com

Teach for America enlists high-performing college grads for two-year stints as teachers in high-need communities. The immediate goal is higher student performance--but Kopp (who originally proposed the concept in her undergraduate thesis) also wants to make teaching the "thing to do." More than 18,000 college seniors vied for 2,900 TFA teaching slots this year, often spurning opportunities with McKinsey, Goldman Sachs, and the like. And while about a third of TFA's 12,000 alumni ultimately leave education, they also include 275-plus principals and the public schools chancellor in Washington, D.C.teachforamerica.org

In 1990, Rice started Nicaragua's first coffee export cooperative--and he figured out that consumers would pay more for "products that also make a difference." A heavy hitter in the fair-trade cabal, TransFair has certified growers employing 1.4 million farmworkers. By selling their coffee beans, tea, cocoa, and other products to buyers willing to pay a premium for certified quality, labor standards, and environmentally sustainable practices, those growers have earned $100 million above market prices since 1998.transfairusa.org

A relative newcomer to microfinance, Unitus has quickly made its mark, helping fund 2.7 million entrepreneurs. Operating in Asia, Africa, and Latin America, it brings consulting services, technology, and capital to build the capacity and effectiveness of microlending institutions, most of them nonprofits. "It might take just 10% to 20% more effort to think 10 times bigger than they've ever thought," Davis says.unitus.com

A military junta forces thousands from their homes in eastern Burma. Landowners enslave 25,000 workers a year in rural Brazil. Witness supports human-rights activists--almost 700 last year in 95 countries--who document such abuses, then edits the video and distributes it to media and lawmakers who can make a difference. Now live: the Hub, which allows anyone, anywhere, to upload and share humanrights-related media.witness.org

Auto workers have the UAW; for independent programmers, writers, and consultants, there's Working Today's freelancer organization. Members get access to health, dental, disability, and life insurance, as well as job boards and networking resources. Most members are still in New York State, but this year, many of the organization's benefits became available nationally.freelancersunion.org

Chertavian wants to "redefine this country's view as to who's talented." So Year Up provides low-income 18- to 24-year-olds with the opportunity to pursue further education and careers that will pay a living wage. Participants get six months of classroom training, followed by six-month apprenticeships in information technology and investment operations with companies such as Merrill Lynch and American Express. Year Up started with 22 students in 2001; this year, it's training more than 500. And some 85% of graduates earn at least $30,000 a year.yearup.org

45 World-Changers

The giant of the microfinance world, ACCION provides partners in 25 nations with technical assistance, financing, and guarantees. Those institutions, in turn, will support 3 million entrepreneurs this year with loans of typically less than $1,000. The idea: Tiny investments, multiplied on mass scale, drive huge gains in income and employment.accion.org